PROJECT SUMMARY While alcohol has been the major substance of misuse in American Indian and Alaska Native (AI/AN) communities for decades and the high rates of alcohol-related morbidity and mortality a major focus of tribal and Indian Health Service (IHS) intervention efforts, the opioid crisis, which is disparately affecting AI/AN people, has amplified the longstanding concerns about the impacts of substance use disorder (SUDs) in this population. Medication assisted treatment (MAT) is a collection of evidence-based interventions that shows particular efficacy for the treatment of alcohol and opioid use disorders, but MAT is vastly underutilized in AI/AN SUD treatment programs. Accounting for the unique cultural and service system contexts that shape SUD treatment in these communities, we propose to build upon mainstream MAT implementation resources to develop and pilot test a two-component intervention combining the provision of online resources as well as access to an Implementation Resource Team that will support programs in their implementation efforts. The specific aims of this proposed project are 1) to work with key stakeholders to adapt extant MAT implementation toolkits and online training programs as well as to develop companion structures and processes to guide the work of an Implementation Resource Team in 2 AI/AN SUD treatment systems; and 2) to test the acceptability, feasibility, and potential utility of the adapted Toolkit and supporting Implementation Resource Team and its implications for conducting a full-scale clinical trial. A blend of community-based participatory and implementation science principles will guide this research effort. In phase 1, two rounds of iterative semi-structured interviews will assess key stakeholders' views across multiple domains in order to guide the adaptation and further development of both web-based materials and the structure and approach that will be employed by the Implementation Resource Team. To test the acceptability, feasibility, and potential utility of the adapted intervention, providers and administrative participants at each site will receive Implementation Resource Team support for 6 months and ongoing access to the web-based resources. At completion of Implementation Resource Team support and again at the end 12-month test period, participants will complete qualitative and quantitative assessments of their experiences with the intervention at their site. Using an interrupted time series design and data extracted from each service system's electronic health records, we will conduct a preliminary assessment of key indicators of MAT implementation (i.e., increase in patient-provider discussions of MAT, increase in MAT prescriptions, increase in MAT-focused follow-up appointments, increase in patients receiving guideline-consistent MAT services). In doing so, we will lay the critical groundwork necessary to advance our knowledge regarding the implementation of MAT to diverse communities, and our ability to reduce the painful impacts that SUDs have on AI/AN communities.